The invention relates to a device for mixing and reacting multiphase gaseous and liquid mixtures wherein non homogeneously miscible liquid homogeneous solutions are brought into intensive contact with homogeneous solutions in which several solid or liquid substances or several gases are dissolved, and to the use of said device, and diphenyl carbonate and polycarbonate prepared with the aid of the device.
It is known to mix homogeneous solutions which are insoluble in one another in order to accelerate the reaction of the individual substances with one another in the solutions. This mixing takes place by stirring, mechanical mixing or the like, as described, for example, in EP 0 228 670 A2, where a process for the preparation of diaryl carbonates is claimed.
A disadvantage of using stirrers or other mechanical mixers is bringing shaft bearings into the stirred-tank reactor or reactor, and the shaft gland out of the stirred-tank reactor or reactor, on the one hand in view of the sealing and on the other hand with regard to the cleaning of the known mixers. The structural design of the shaft bearings as a shaft gland in large stirred-tank reactors is therefore very complex and associated with considerable expense.
Moreover, the known stirred-tank reactors or mixers cannot be enlarged at will since a chemical reaction also frequently takes place during mixing, so that enthalpy of mixing and/or reaction is liberated or required in the reactor during the mixing process. In order to dissipate the enthalpy towards the outside or to feed it into the interior of the reactor, additional heat exchangers are required in the case of very large mixers, since the ratio of heat exchange surface to the reactor volume decreases as the stirred-tank reactor radius increases. In these cases, the stirred-tank reactor volume is reduced by increasing the number of stirred-tank reactors, or the heat transport is intensified by providing additional heat exchangers in the secondary flow.
The object of the invention is, therefore, to improve the known device described in more detail above for mixing and reacting multiphase gaseous and liquid mixtures in such a manner that, with little structural complexity, a structurally small mixer is provided which dispenses with shaft bearings and shaft glands in order to avoid the disadvantages described above. Moreover, the quality of the mixture should be improved.
The object is achieved by a nozzle mixer as a reactor with a cylindrical space for the entry of the first solution, at least one cylindrical chamber tapering towards the space, in which chamber the mixing and reaction of at least two solutions takes place, a cylindrical space arranged perpendicularly to the space for the inflow of the second solution, and a space for the outflow of the mixed and reacted solutions out of the nozzle mixer. In order to the reduce the pressure drop, the outflow space in a further embodiment of the invention is provided with a conically widening cross-section.